The invention relates to an axial flow combine harvester and in particular to a feed plate for directing crop material into the rotor for threshing and separation.
Crop material is fed tangentially into the threshing cylinder of a conventional combine. Tangential feed is an easy and uncomplicated method of conveying crop material. Conveying crop material into the end of an axial flow rotor housing on the other hand is not an easy matter. The most significant patents to issue on axial flow combines have been concerned with conveying crop material into the housing for an axial flow rotor.
Funnels have been provided at the front of the rotor housing with screw conveyors on the forward end of the rotor and inside the funnel. Fans have been used to blow crop material into a rotor housing. Attempts have been made to suck crop material into rotor housings. Various beater configurations have been tried to force crop material into rotor housings. Screw conveyors have been suggested which would force feed crop material into a rotor housing.
All of the above-mentioned feeding methods for feeding crop material to an axial flow rotor and into a rotor housing have disadvantages. The power required to drive the feeding mechanisms is excessive in some. The quantity of material that can be fed into the threshing and separating mechanisms is limited in some. Wear on portions of the inlet end of the axial flow rotor is excessive in some.
The elevator to the cylinder on a conventional combine harvester generally houses a chain and slat conveyor or a beater conveyor. The beater conveyors have a beater immediately in front of the threshing cylinder. The chain and slat conveyors often employ a beater between the discharge end of the chain and slat conveyor and the threshing cylinders. With both types of elevators to the cylinder, the crop material is pressed into a continuous mat that is relatively thin and the width of the elevator housing. This mat of crop material tends to hold together. Under most conditions, it is easy to convey. A conventional combine cylinder receives the mat tangentially and moves it along the arcuate surface of a concave. As the mat of crop material moves along the concave, it is accelerated and the grain is threshed from the heads.
A mat of crop material moves from a standard elevator to the cylinder and enters an axial flow rotor housing in a plane that is inclined upwardly and rearwardly relative to the direction of travel of the machine. This mat of crop material contacts a threshing and separating rotor that rotates about an axis that is close to horizontal and lies in a vertical plane that extends in a fore and aft direction relative to the harvester. The center portion of the mat of crop material makes an essentially point contact with the rotor and the side portions of the mat must be cramed into the rotor housing some way. The point contact results in fast wear on the surface of the rotor. The poor feeding of the edges of the mat of crop material into the rotor casing decreases the capacity of the harvester and reduces harvester efficiency.